Rivers run deep, high, and wild

Last week I read Matt Edgeworth’s book on the archaeology of rivers. It is a short book but it contains plenty of interesting examples for my own study on water as an archaeological object. I will describe three of these examples. For Edgeworth “most rivers are neither natural nor cultural, but rather entanglements of both” (p 15). He calls rivers “wild artefacts” since their form cannot be controlled. Water management implies a manipulation of the water source.

The first example I choose to describe from Edgeworth’s book is a classic study by Leopold and Wolman. They studied small rivers in Maryland and Pennsylvania and this resulted in the creation of a standard type of natural watercourse, supposedly unaffected by human modification. It later turned out that the channels had been modified by colonial period mill dams. Sediment accumulated behind the mill dams and below these sediments Walter and Merritts found evidence of another kind of river with multiple branching channels. The new study showed that the modern, incised, meandering form was the result of human utilization of streams for power.

Another of Edgeworth’s examples deals with the levees of the Yellow River in China. Levees are parallel to the direction of the current and they channel water. When the Yellow River floods it deposits sediments that build it upwards. When the river rises above the surrounding floodplain people needs to raise the levees, etc. At some places the river runs up to ten m above the surrounding terrain. In 1861 the river escaped the channel and six years later it flowed into the sea, 500 miles north of the old mouth. 26 major changes in the course of the river are known from the past 3000 years. The river has also been used in warfare. In 1938 the Chinese forces cut a gap in a levee so that the river swept away advancing Japanese forces. This had long-term negative effects as hundreds of thousands of local people drowned. Not until 1946 could the river be returned to its former course.

The third example concerns the infamous “Vildhussen” (Magnus Huss) in Sweden. In 1794 Huss began to excavate a canal through a dam of glacial material located in the eastern end of Lake Ragunda. This was done in order to bypass the Storforsen rapids in River Indal (Indalsälven) which was disastrous for transporting logs. This new canal would make it easier to move logs. However, in 1796, the spring floods breached the dam. Storforsen was transformed into Döda fallet(The dead waterfall). Upstream the drained Lake Ragunda was transformed into a fertile plain. Downstream huge amounts of sediment re-deposited on the Indal delta and formed the island where Midlanda airport is located. When I was still in the military service I was supposed to be stationed at Midlanda airport in case of war (I was part of an air defense unit). At that time I had no idea that Midlanda island was the result of Vildhussen’s hyss (mischief).